The servo mechanism is an important part of the missile attitude control system. Its performance has great influence on the attack accuracy and accuracy of the missile's attitude control, and even decides the success or failure of the missile's flight. First, the mathematical model of the system is established on the basis of analyzing the structural mechanism of an electric servo mechanism for a certain type of missile and the working principle. Then, the three closed-loop control of the position, speed and current is used for the model. The step response methods based on time domain and the sinusoidal correlation analysis methods based on frequency domain are applied to simulate dynamic performance on the Matlab/Simulink simulation platform. Finally, the dynamic characteristics of the model meet the requirements of technical indicators, and the scientific rationality of the model is also illustrated. Therefore, it is of great engineering significance to lay a solid foundation for further research on this type of servo mechanism.